Monthly Archives: November 2008

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Remember the first Boeing 777 crash ever? I wrote about it here when it happened on the 17th of January. I initially suspected that it was wind shear that caused the crash. But it wasn’t. I recently read an interesting article and the author blamed it on pilot error. Here’s what he thinks happened.

Flight BA038 was on a holding pattern above Heathrow when the ATC told them that they could come in for a landing early. In order to make that landing, they would have to slow the plane down considerably. There are a few ways of slowing a plane down. Speed brakes (air brakes) and flaps can be used. Engine power can be reduced also, but only to a certain extent and under certain conditions only.

The pilots made a big mistake when they reduced the engine power below the recommended threshold for safe flight. You see, aircraft turbine engines are very different from car piston engines. A car’s engine can rev from idle to max rpm in a matter of seconds. The Boeing 777 engines (Rolls Royce Trent 800) on the other hand requires up to 12 seconds to spool up from idle and give maximum thrust. The pitch up attitude (nose up) of the aircraft during approach made matters worse because the airflow entering the engine inlet is at an angle and airflow to the compressors is affected. This coupled together with the low engine rpm creates a very favorable condition for stalling and surging of the engine to occur. Stalling and surging can cause a loss of thrust and can also cause an engine to flame out and shut down. In more serious cases, the whole engine can be destroyed.

So back to our situation. The pilots of flight BA038 pulled back on the throttles too much to descent quickly. Doing so caused the engines to spool down and reduce the output thrust. The plane slowed down and in order to maintain lift, they pulled back on the control columns, causing the plane to fly at a nose up attitude. This positioned the engine intakes at an angle to the incoming air which as explained above affects the airflow into the engine.

During the approach, they lowered the landing gears and flaps and with the extra drag caused by the landing gears and flaps, the plane started to drop. They realized that they needed more lift (read: more thrust) to make it to the runway. Remember at this point the engines are at low rpm and the engine intakes are not at the proper angle with the incoming airflow. They pushed the throttles forward to increase thrust, but as the engine tries to spool up, the unfavorable conditions caused them to surge. When a surge happens, there is a loss of thrust and loud booms can be heard. With a loss of thrust, there will be a loss of lift. Passengers recalled hearing loud sounds coming from the engines and also an unusually steep descend (quote “we just dropped”). The captain claimed that “there wasn’t power” when he needed it.

If you’ve been following what I’m trying to say, you’ll know why there wasn’t any power when the throttles were opened. The engine needed time to recover from the surge, and at such low rpm, it would have taken 12 seconds for it to go to full thrust. 12 seconds was time that they didn’t have. To make the story short, the plane lost lift, descended too quickly and hit the ground before it reached the runway and became the first Boeing 777 to crash.

As the author mentioned, they shouldn’t have reduced thrust too much during approach and should have trusted the computer when it insisted that thrust should be maintained at a higher level. In fact, I had a chat with virtualmystic and he said that normally throttles shouldn’t be touched during the approach. Any deviation of the aircraft from the glideslope (ILS) should be corrected by using the control column as it gives better response.

Disclaimer: I don’t guarantee or claim that the above are 100% correct because I’ve not read the official report or seen the FDR data. It’s just a speculation that I find interesting and logical. But if you think I’m wrong, do drop me a line. I’ll be happy to hear your reasoning. As always, happy flying! Continue reading →

Long overdue post. On 1st Nov, few of us decided to go get cheap beers again at the OktoberFest held at 1Utama. We were there last year also. Where else can you get a bottle of beer for RM1 (2 50sen coins)?

Waiting in line for extra servings.

This year they started it late at 7pm instead of 5pm. The queue is incredible. But I’m quite sure this year they have more than 1000 bottles to give away. We managed to get 3 bottles each.

What inconvenience?

There’s a good story behind this photo. The guy beside me was by himself so we asked him to help us take a photo. He was probably drunk because he joined us in the photo instead.

2 plus bottles on an empty stomach later, we went to KFC to wash all that beer down.

Look, we’re not drunk. Security guard keeping a close eye on us.

Then we went for a round of drunken bowling. I think I actually bowled better.

Tan selecting his balls.

Our lanes.

Best bowler of the day*

Nothing like a good night out with cheap beers. Will be waiting for the next Oktoberfest! Continue reading →

Final Verdict
Two weeks of testing and countless hours of watching DVDs and videos later, the Samsung DVD-1080pk has proven itself to be a worthy and invaluable companion in the living room. With its sleek black design, you’ll be sure that it will match your other AV equipment nicely.

Samsung DVD-1080PK.

Perhaps the DVD-1080PK wasn’t targeted at consumers looking for a player that will just play DVDs. With tons of extra features and compatibility with HD displays, it gives the impression that it was designed not to go obsolete anytime soon. Users will not need to upgrade when they purchase a HD display in the future because it comes with a HDMI port, ready to blast out movies in full HD.

HDMI cable provided as well.

Tech savvy consumers who have always dreamed of having a PC in the living room will find the DVD-1080PK somewhat fulfilling their needs. With a USB port and support for thumbdrives and portable hard disks, downloaded movies, videos and songs can be enjoyed in Full HD and 5.1 channel surround sound. Need to back up your CDs to MP3s? No problem, its just a button away.

Watch videos in the comfort of your living room with the USB host function.

The days of unplayable DVDs are over with the DVD-1080PK. With Samsung’s No.1 in Playability, all DVDs, regardless of condition (except cracked ones) can be played and so far I’ve not had a problem with DVDs skipping. Playback is fast and effortless. Put the DVD in and automatic playback ensures that you’ll be enjoying your movie within seconds. The ease of use of the playback controls means you’ll spend more time watching your movie than fiddling with the remote.

Works well with older TVs too.

Besides some minor issues with the player, there are no real reasons not to get the Samsung DVD-1080PK. With so much features packed into it, I daresay that this will be the only DVD player that you’ll need for a long long time.

Issues.
After testing the DVD-1080PK for two weeks, I have found little to hate about this player. However there are some issues which I would like to point out.

1. Image loading is slower than desired.

This player probably hasn’t got tons of processing power to render jpgs as fast as I like it. A typical jpg file takes about 10 seconds to load. This is not noticeable during a slide show but when you’re viewing photos manually with the remote, this can be frustrating. But I rarely use my DVD player to view photos so this won’t affect me much. If I want fast, I’ll plug my D80 to the TV.

2. Menu interface is sluggish.

Playback controls (play, stop, pause etc) are fast and responsive but navigating through the player’s menus is slow. You press the button and only a second later, you’ll get a response. It feels about the same as operating your ASTRO decoder. Again, this may be because I’m more used to the responsiveness of a computer.

3. Minor build quality issues.

Tray door slightly misaligned with the opening.

When you mix plastics and mass production, it’s rarely possible to get proper tolerances. The player looks great sitting there far away from you. But upon closer inspection, a few defects can be seen. The most obvious being the disc tray door not aligned properly (see photo above). Others are located elsewhere and are not that visible unless you look carefully.

Overall, like I’ve said, I don’t have much to complain about this DVD player. I would prefer a faster and more responsive interface. But then again I don’t spend the whole day fiddling with my DVD player. I use it to watch movies. So a sluggish interface may not be such a big problem.

We all hate putting in DVDs and then only to find that they can’t be played because of some mysterious reason. Could be a small scratch, or a slight deformation due to heat or manufacturing defect. Sometimes this happens even if you keep your DVDs properly. Obviously something needs to be done about this, and Samsung thinks that it has the solution.

Disc stacking. Popular with people who have too many CDs.

The DVD-1080PK, which Samsung claims to have No.1 in Playability, features Samsung’s rolling actuator technology. Instead of having a read head that moves up and down, it has one that rolls on its axis. Samsung claims that it improves readability on deformed discs. Read here for more info and animation on how it works.

It looks good on paper, but how would it fare in a real-world test? Let’s find out.

Normal wear and tear

Some people are just too lazy to store their DVDs properly or simply couldn’t care less. Everything is thrown into a box or a drawer and sometimes the DVDs are not even put inside their protective covers. Small scratches will develop as a result. These are hairline scratches which you can find in almost all discs and they generally won’t pose a problem for the players.

Method: For this test, I had lots of good candidates from my box of CDs. I picked a few with hairline scratches, some with deeper ones and put them into the player. I also borrowed some which are in excellent condition which were kept in their covers most of the time.

Results: As expected, ALL of them played without problems. No skipping whatsoever. Scratches won’t affect the data on a DVD much, unless the scratch is so deep that it punctures through to the other side.

Severe mishandling

I’m talking about little brothers and sisters playing UFOs with your DVD collection. Or someone using your DVDs to train their wrist muscles. This is not categorized under normal wear and tear and if your DVDs suffer from this kind of abuse, it’s time to rethink your choice of movies.

Method: Took a few DVDs and tried in vain to bend them. They’re tough, won’t break easily. And the bending was not enough to deform the discs. Threw some around the room.

Results: All played with flying colors. No signs of damage at all. In fact, DVDs that have been bent looked physically better than DVDs with scratches because they suffered no damage because of the bending.

In order to cover all possible scenarios, and since the DVD player passed all the above tests, we’ll try something more fun. The scenarios below will not ever happen if you take care of your DVDs.

Left outside under the sun

The sun gives out heat and harmful UV rays, everything that’s bad for plastics. Leaving CDs under the sun is a no no. But let’s say you somehow left your DVD on the driveway one day.

Method: Took a boring DVD and left it under the afternoon sun.

Results: No visible damage. The DVD played with no problems at all. I was expecting at least some warping to take place. Maybe it would have warped if I had left it for a week. But if it has been left for a week, it probably wasn’t worth watching anyways.

Run over by a car

Imagine you’re holding a DVD in one hand while driving and suddenly your hand slipped and you run over it with your car. It could never happen. But just in case.

Method: Drive car over disc.

Results: The disc was cracked in several places. The player detected no disc so it cannot be played. It was probably because the disc was broken in a few places.

Frozen in a freezer

You might be holding your favorite DVD while making ice in the freezer and somehow you managed to drop the DVD into the freezer without knowing it. The next day, you end up with a DVD encased in ice.

Method: Put DVD in a tub of water and leave it in the freezer overnight. Defrost before attempting to play in player.

Results: Again, no evident damage on the DVD and it plays perfectly on the DVD player.

Flamed

One day you’re boiling eggs while holding a DVD in one hand. You somehow slipped and the DVD landed on the stove above the open flame. You turn off the flame but it was already too late.

Method: Put DVD on stove and turn on the fire. Cook for 5 seconds. Leave to cool before attempting to play it.

Results: Finally I managed to get a warped disc. Watch video below to see the difference between a warped disc and a normal one. Hint: it wobbles.

And guess what? To my surprise, it played perfectly! It was amazing because I saw the disc twist and warp at the stove and I thought it was destroyed already. Amazing. If your DVD sustained this level of damage, you should not be allowed to handle them.

Conclusion

This DVD player seems to play everything that I throw at it, with the exception of the cracked DVD. It even plays discs that have gone through serious mishandling and negligence. I don’t know how far I can push it but I think I can safely say that for a typical home user, this player will play all your DVDs regardless of its condition. For the past 2 weeks that I have been testing it, I have not had a DVD that will not play in this player.